Question

I want to run python code from C# through command Prompt.The Code is attached below

    Process p = new Process();
    p.StartInfo.FileName = "cmd.exe";
    p.StartInfo.WorkingDirectory = @"d:";
    p.StartInfo.WindowStyle = ProcessWindowStyle.Normal;
    p.StartInfo.UseShellExecute = false;
    p.StartInfo.RedirectStandardOutput = true;
    p.StartInfo.RedirectStandardInput = true;

    p.Start();
    p.StandardInput.WriteLine(@"cd D:\python-source\mypgms");
    p.StandardInput.WriteLine(@"main.py -i example-8.xml -o output-8.xml");

    string output = p.StandardOutput.ReadToEnd();
    p.WaitForExit();

    Console.WriteLine("Output:");
    Console.WriteLine(output);

Output :

D:\python-source\mypgms>main.py -i example-8.xml -o output-8.xml

D:\python-source\mypgms>

But nothing happened.Actually main.py is my main program and it takes 2 arguments. one is input xml file and another one is converted output xml file.

But i dont know how to run this python script from C# through command prompt. Please Guide me to get out of this issue…

Thanks & Regards,
P.SARAVANAN

Answer 1

I think you are mistaken in executing cmd.exe. I’d say you should be executing python.exe, or perhaps executing main.py with UseShellExecute set to true.

At the moment, your code blocks at p.WaitForExit() because cmd.exe is waiting for your input. You would need to type exit to make cmd.exe terminate. You could add this to your code:

p.StandardInput.WriteLine(@"exit");

But I would just cut out cmd.exe altogether and call python.exe directly. So far as I can see, cmd.exe is just adding extra complexity for absolutely no benefit.

I think you need something along these lines:

var p = new Process();
p.StartInfo.FileName = @"Python.exe";
p.StartInfo.Arguments = "main.py input.xml output.xml";
p.StartInfo.WorkingDirectory = @"D:\python-source \mypgms";
p.StartInfo.WindowStyle = ProcessWindowStyle.Normal;
p.StartInfo.UseShellExecute = false;
p.StartInfo.RedirectStandardOutput = true;
p.Start();
p.WaitForExit();

Also the Python script appears to output to a file rather than to stdout. So when you do p.StandardOutput.ReadToEnd() there will be nothing there.